| Message ID | 20210401233216.2540591-14-samitolvanen@google.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | Add support for Clang CFI | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
On Thu, Apr 01, 2021 at 04:32:11PM -0700, Sami Tolvanen wrote: > With CONFIG_CFI_CLANG, the compiler replaces function address > references with the address of the function's CFI jump table > entry. This means that __pa_symbol(function) returns the physical > address of the jump table entry, which can lead to address space > confusion as the jump table points to the function's virtual > address. Therefore, use the function_nocfi() macro to ensure we are > always taking the address of the actual function instead. > > Signed-off-by: Sami Tolvanen <samitolvanen@google.com> > Reviewed-by: Kees Cook <keescook@chromium.org> > --- > arch/arm64/include/asm/mmu_context.h | 2 +- > arch/arm64/kernel/acpi_parking_protocol.c | 3 ++- > arch/arm64/kernel/cpu-reset.h | 2 +- > arch/arm64/kernel/cpufeature.c | 2 +- > arch/arm64/kernel/psci.c | 3 ++- > arch/arm64/kernel/smp_spin_table.c | 3 ++- > 6 files changed, 9 insertions(+), 6 deletions(-) > > diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h > index bd02e99b1a4c..386b96400a57 100644 > --- a/arch/arm64/include/asm/mmu_context.h > +++ b/arch/arm64/include/asm/mmu_context.h > @@ -140,7 +140,7 @@ static inline void cpu_replace_ttbr1(pgd_t *pgdp) > ttbr1 |= TTBR_CNP_BIT; > } > > - replace_phys = (void *)__pa_symbol(idmap_cpu_replace_ttbr1); > + replace_phys = (void *)__pa_symbol(function_nocfi(idmap_cpu_replace_ttbr1)); > > cpu_install_idmap(); > replace_phys(ttbr1); > diff --git a/arch/arm64/kernel/acpi_parking_protocol.c b/arch/arm64/kernel/acpi_parking_protocol.c > index e7c941d8340d..bfeeb5319abf 100644 > --- a/arch/arm64/kernel/acpi_parking_protocol.c > +++ b/arch/arm64/kernel/acpi_parking_protocol.c > @@ -99,7 +99,8 @@ static int acpi_parking_protocol_cpu_boot(unsigned int cpu) > * that read this address need to convert this address to the > * Boot-Loader's endianness before jumping. > */ > - writeq_relaxed(__pa_symbol(secondary_entry), &mailbox->entry_point); > + writeq_relaxed(__pa_symbol(function_nocfi(secondary_entry)), > + &mailbox->entry_point); > writel_relaxed(cpu_entry->gic_cpu_id, &mailbox->cpu_id); > > arch_send_wakeup_ipi_mask(cpumask_of(cpu)); > diff --git a/arch/arm64/kernel/cpu-reset.h b/arch/arm64/kernel/cpu-reset.h > index ed50e9587ad8..f3adc574f969 100644 > --- a/arch/arm64/kernel/cpu-reset.h > +++ b/arch/arm64/kernel/cpu-reset.h > @@ -22,7 +22,7 @@ static inline void __noreturn cpu_soft_restart(unsigned long entry, > > unsigned long el2_switch = !is_kernel_in_hyp_mode() && > is_hyp_mode_available(); > - restart = (void *)__pa_symbol(__cpu_soft_restart); > + restart = (void *)__pa_symbol(function_nocfi(__cpu_soft_restart)); > > cpu_install_idmap(); > restart(el2_switch, entry, arg0, arg1, arg2); > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > index e5281e1c8f1d..0b2e0d7b13ec 100644 > --- a/arch/arm64/kernel/cpufeature.c > +++ b/arch/arm64/kernel/cpufeature.c > @@ -1462,7 +1462,7 @@ kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused) > if (arm64_use_ng_mappings) > return; > > - remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings); > + remap_fn = (void *)__pa_symbol(function_nocfi(idmap_kpti_install_ng_mappings)); > > cpu_install_idmap(); > remap_fn(cpu, num_online_cpus(), __pa_symbol(swapper_pg_dir)); > diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c > index 62d2bda7adb8..e74bcb57559b 100644 > --- a/arch/arm64/kernel/psci.c > +++ b/arch/arm64/kernel/psci.c > @@ -38,7 +38,8 @@ static int __init cpu_psci_cpu_prepare(unsigned int cpu) > > static int cpu_psci_cpu_boot(unsigned int cpu) > { > - int err = psci_ops.cpu_on(cpu_logical_map(cpu), __pa_symbol(secondary_entry)); > + int err = psci_ops.cpu_on(cpu_logical_map(cpu), > + __pa_symbol(function_nocfi(secondary_entry))); Could we use a temporary here, e.g. phys_addr_t pa_secondary_entry = __pa_symbol(function_nocfi(secondary_entry)); int err = psci_ops.cpu_on(cpu_logical_map(cpu), pa_secondary_entry); > if (err) > pr_err("failed to boot CPU%d (%d)\n", cpu, err); > > diff --git a/arch/arm64/kernel/smp_spin_table.c b/arch/arm64/kernel/smp_spin_table.c > index 056772c26098..4c4e36ded4aa 100644 > --- a/arch/arm64/kernel/smp_spin_table.c > +++ b/arch/arm64/kernel/smp_spin_table.c > @@ -88,7 +88,8 @@ static int smp_spin_table_cpu_prepare(unsigned int cpu) > * boot-loader's endianness before jumping. This is mandated by > * the boot protocol. > */ > - writeq_relaxed(__pa_symbol(secondary_holding_pen), release_addr); > + writeq_relaxed(__pa_symbol(function_nocfi(secondary_holding_pen)), > + release_addr); Likewise here? e.g. at the start of the function have: phys_addr_t pa_holding_pen = __pa_symbol(function_nocfi(secondary_holding_pen)); ... then here have: writeq_relaxed(pa_holding_pen, release_addr); With those: Acked-by: Mark Rutland <mark.rutland@arm.com> Thanks, Mark. > __flush_dcache_area((__force void *)release_addr, > sizeof(*release_addr)); > > -- > 2.31.0.208.g409f899ff0-goog >
diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h index bd02e99b1a4c..386b96400a57 100644 --- a/arch/arm64/include/asm/mmu_context.h +++ b/arch/arm64/include/asm/mmu_context.h @@ -140,7 +140,7 @@ static inline void cpu_replace_ttbr1(pgd_t *pgdp) ttbr1 |= TTBR_CNP_BIT; } - replace_phys = (void *)__pa_symbol(idmap_cpu_replace_ttbr1); + replace_phys = (void *)__pa_symbol(function_nocfi(idmap_cpu_replace_ttbr1)); cpu_install_idmap(); replace_phys(ttbr1); diff --git a/arch/arm64/kernel/acpi_parking_protocol.c b/arch/arm64/kernel/acpi_parking_protocol.c index e7c941d8340d..bfeeb5319abf 100644 --- a/arch/arm64/kernel/acpi_parking_protocol.c +++ b/arch/arm64/kernel/acpi_parking_protocol.c @@ -99,7 +99,8 @@ static int acpi_parking_protocol_cpu_boot(unsigned int cpu) * that read this address need to convert this address to the * Boot-Loader's endianness before jumping. */ - writeq_relaxed(__pa_symbol(secondary_entry), &mailbox->entry_point); + writeq_relaxed(__pa_symbol(function_nocfi(secondary_entry)), + &mailbox->entry_point); writel_relaxed(cpu_entry->gic_cpu_id, &mailbox->cpu_id); arch_send_wakeup_ipi_mask(cpumask_of(cpu)); diff --git a/arch/arm64/kernel/cpu-reset.h b/arch/arm64/kernel/cpu-reset.h index ed50e9587ad8..f3adc574f969 100644 --- a/arch/arm64/kernel/cpu-reset.h +++ b/arch/arm64/kernel/cpu-reset.h @@ -22,7 +22,7 @@ static inline void __noreturn cpu_soft_restart(unsigned long entry, unsigned long el2_switch = !is_kernel_in_hyp_mode() && is_hyp_mode_available(); - restart = (void *)__pa_symbol(__cpu_soft_restart); + restart = (void *)__pa_symbol(function_nocfi(__cpu_soft_restart)); cpu_install_idmap(); restart(el2_switch, entry, arg0, arg1, arg2); diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index e5281e1c8f1d..0b2e0d7b13ec 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1462,7 +1462,7 @@ kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused) if (arm64_use_ng_mappings) return; - remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings); + remap_fn = (void *)__pa_symbol(function_nocfi(idmap_kpti_install_ng_mappings)); cpu_install_idmap(); remap_fn(cpu, num_online_cpus(), __pa_symbol(swapper_pg_dir)); diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c index 62d2bda7adb8..e74bcb57559b 100644 --- a/arch/arm64/kernel/psci.c +++ b/arch/arm64/kernel/psci.c @@ -38,7 +38,8 @@ static int __init cpu_psci_cpu_prepare(unsigned int cpu) static int cpu_psci_cpu_boot(unsigned int cpu) { - int err = psci_ops.cpu_on(cpu_logical_map(cpu), __pa_symbol(secondary_entry)); + int err = psci_ops.cpu_on(cpu_logical_map(cpu), + __pa_symbol(function_nocfi(secondary_entry))); if (err) pr_err("failed to boot CPU%d (%d)\n", cpu, err); diff --git a/arch/arm64/kernel/smp_spin_table.c b/arch/arm64/kernel/smp_spin_table.c index 056772c26098..4c4e36ded4aa 100644 --- a/arch/arm64/kernel/smp_spin_table.c +++ b/arch/arm64/kernel/smp_spin_table.c @@ -88,7 +88,8 @@ static int smp_spin_table_cpu_prepare(unsigned int cpu) * boot-loader's endianness before jumping. This is mandated by * the boot protocol. */ - writeq_relaxed(__pa_symbol(secondary_holding_pen), release_addr); + writeq_relaxed(__pa_symbol(function_nocfi(secondary_holding_pen)), + release_addr); __flush_dcache_area((__force void *)release_addr, sizeof(*release_addr));